With a warming and drying climate, coniferous forests worldwide are increasingly threatened by wildfires. We examined how fire impacts ectomycorrhizal (EM) fungi associated with Pinus ponderosa, an important tree species in western North America. In the biodiverse Madrean Sky Islands, P. ponderosa forests exist on insular mountains separated by arid lands. How do EM fungi in these isolated ranges respond to fire, and can data from individual ranges predict community shifts after fire at a regional scale? By comparing areas in two ranges that experienced moderate fires 12–16 y earlier, and proximate areas in each range without recent fire, we reveal pervasive effects on diversity and composition of EM communities more than a decade after moderate fires occurred. Post-fire differences in EM communities in different ranges highlight the challenge of predicting fungal community shifts in these isolated forests, despite similarities of climate, plant communities, and fire severity.

随着气候的变暖和干燥，全世界的针叶林越来越受到野火的威胁。我们研究了火如何影响与北美西部重要树种美国黄松相关的外生菌根（EM）真菌。在生物多样性的马德里安天空群岛中，美国短毛猴在由干旱土地隔开的岛屿山上有森林。这些孤立范围内的EM真菌如何应对火灾，并且各个范围内的数据能否预测区域范围内火灾后的社区转移？通过比较两个范围内发生过12-16年中度火灾的区域以及每个范围中没有发生过近期火灾的区域，我们揭示了中等程度火灾发生十多年后，对新兴市场社区的多样性和组成的普遍影响。尽管气候，植物群落和火灾严重程度相似，但在不同范围内的EM群落发生火灾后的差异凸显了预测这些孤立森林中真菌群落转移的挑战。